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15k RPM IDE Hard Drives?
OutRigged asks: "SCSI hard drives have had speeds in excess of 10,000RPM for years, yet IDE has always been stuck at 7200RPM. Is there some kind of technical reason IDE drives don't go above 7200RPM? I can't imagine cost being that big of an issue, and the connection is certainly not a problem, with Parallel ATA capable, at least theoretically, of speeds over 100MB, and Serial ATA capable of even more. With hard drives now reaching sizes in excess of 300GB, don't you think we need a speed increase?" If you are wondering what the terms "Parallel ATA" and "Serial ATA" refer to, check out this article.
I've always wondered, why not simply connect all those harddrives with gigabit ethernet? Seems to be as fast, available, can be connected/disconnect while computer is on, can be used over much greater distances, etc, etc.
SCSI drives are built to a much higher standard than IDE drives, especially the 10K RPM drives. Cost is a huge issue, especially when much faster spindle rates are concerned. Increase the rotational inertia and speed and you have to have a pretty fancy bearing system to cope with these loads. This sounds simple, and it is, but it is not cheap. The greater the rotational inertia a drive has, many aspects like passive cooling, fancy materials have to be considered vs the intended consumer of such a drive. Typically, SCSI drives are used by corporations that usually have a nice service contract attached to the hardware. In terms of IDE, which is the end-user and home market of such a device, coupled with the limitations of the IDE interface combined with Microsoft's problematic IO/IDE software, and we realize that going faster does nothing for anyone. Except for maybe driving up costs for everyone involved and curtailing the MTBF figures. If anyone will do it, WD will, what with its fluid bearings. But, we shall see =).
Initially it will run at arround 150Megabytes a second, however should be able to increase to 600.
AFAIK, the spinning mechanics of SCSI drives are the same as IDE ones, just that they are generally machined to a higher spec than the IDE ones. Another "let's give the common people something less durable, banking on that it won't be used as hard" thing.
Note the recent move to 1 year warrenties on IDE hard drives. SCSI drives are still 3-5 years. Honestly, I'm seriously thinking of doing SCSI in my next computer. Two years ago, I got a new computer and got ATA in it. It's been a good computer, but it's starting to feel it's age. My previous computer had scsi in it, and was a dual processor. The extra money I spent (almost 3k when I bought it) helped it last an extra year over theis one as far as speed was concerned.
If you do any serious disk activity, SCSI is a very very good way to go. If you plan on more than one person on a computer at a time, go scsi. For instance, I have a coworker who runs windows 2k at work and has Terminal Services running in admin mode. I logged in and started installed cygwin on it (we're testing cfengine on windows), and it hammered his machine. Made it unusable. That was just downloading stuff to disk! It's a p4 1.7 dell desktop job. My dual p3-700 with scsi never experienced anything like that until both processors were hammered running chemistry code and doing heavy disk activity.
I don't have any empirical data, I just have experienced too much IDE sub-standardness. You pay extra money for a reason, but I personally think it's money well spent.
-- Who is the bigger fool? The fool or the fool who follows him? --
Some of the newer CD drives have two (or more?) 'heads', so they can read simultaneously, effectively doubling the access speed without increasing the speed of spinning. I was wondering: Can't the same be done for hard drives?
Apparently I'm not even the first one to suggest this -- for example, see here.
- Tal Cohen
It IS expense...so often we forget, but only recently were harddrive manufacturers having problems with their 7200RPM and in some cases even 5400RPM drives. The reason is heat. If you check around, you'll find that the largest 15000RPM drive is made by Seagate (it's ~80GB and it's ~$1000)...why???
When you raise the number of bits per inch of storage surface you create more stress and heat. When you raise the RPMs you create more heat (alot @15000RPM). The overall effect is that you can't use the cheap parts that are used in most IDE drives...every piece of the drive must be manufactured to the highest specifications. Motors have to be of the highest quality. Hydrodynamic bearings must be used instead of metal ball-bearings...this all increases the cost (as it pushes the technology).
The reason why these faster drives are not sold as IDE is simple. Anyone who is willing to pay $1000 for a ~80GB harddrive is also willing to pay $75 for a decent controller card (if it's not already built into their workstation).
How many ppl are going to be willing to pay $1000 for an 80GB IDE drive when they can buy a 300GB drive for 1/3 the cost? The end result is that most consumers simply don't care about the speed...the majority of IDE drives go into OEM systems and the consumer probably won't know if they put a 4500RPM drive in the system.
So, why not get the best of both worlds. Buy a 20GB 15000RPM SCSI and put your system files and most widely used apps on that (~$130 for a 18G Seagate). And then buy a larger IDE drive for archives.
When you think about it, you shouldn't need more than 20GB for your system, apps, and maybe a few games.
As far as the slower IDE drive, just spend your money on more RAM for the system and increase the cache. And don't rely on the CPU intensive built-in IDE controller on most Intel/AMD motherboards...buy a decent controller card instead.
And if you really want to get ~15000RPM with IDE technology, just get an IDE RAID controller and use striping...using this method you can actually get to much higher theoretical speeds than a single 15000RPM drive. with 4 7200RPM drives you could get up to a theoretical speed of 28800RPM!!!
You want to know *why* people don't try looking for 15K RPM drives on IDE? Most IDE drives are built to be as cheap as possible. People look for the following, in order (I suspect that a lot of them wish in retrospect that they had put reliability first).
* Cost
* Size
* Reliability (unfortunately, hard to measure...MBTF is kind of BS)
* Noise
* Speed
* Heat
I tend to move Heat higher up, given the impact it has on Noise and Reliability.
And, you know what? For most applications (workstation) hard drive speed is completely a non-issue. HD transfer rates improve over time *anyway*. If you increase aureal density but keep rotational speed the simple, you're increasing peak non-cache data transfer rate. So you get a faster hard drive now than you used to. Second, for the vast majority of workstation applications, hard drive time is simply not important. It's almost never the bottleneck for critical applications. If you're paging, yes, but RAM is cheap and does such a far better job that you're better adding another 512MB of RAM to your system. File copies are rarely a problem -- you don't need to remove a hard drive, so you can just background the copy and forget about it, unlike in the days of floppies. If it's a copy to/from removable media, it's almost always the removeable media that's the bottleneck, not the drive, so more drive speed will give you basically nothing.
The other thing to remember is that RAM caching is far better than it once was (partly based on sheer amount of memory). Most of the time, your working data set will fit into memory just fine, and be cached. Linux has very good disk caching. Windows less so, but still much better than the dark days of 9x. And a silly little difference like a 5200 RPM drive being 25% slower than a 7200 RPM drive pales in comparison to the thousand or so times faster that your memory is. You're almost always better off getting more solid-state storage and not trying to work the bejeezus out of the mechanical parts of your hard drive.
I would never recommend anything but a 5400 RPM IDE drive to anyone. 7200 and above will buy you heat issues, reliability issues, and noise issues. Tack on a fan and you help a bit with heat (of course, having "hot spots" in your drive and then heavily cooled spots isn't great either), but then you get more dust, and more noise. Of all the people I know, all the drives in the past three years that failed have been 7200 RPM, not 5400 RPM. That speed difference isn't huge to you, and is far nicer to the cheap, fragile mechanism in the hard drive.
In conclusion -- buy 5400 RPM. You'll be a lot happier.
May we never see th
maybe i should just start selling ceramic heaters in a regular hard drive profile, attach a 512mb compact flash card, and claim it's a half-gig 20,000 rpm drive. people'd probably believe me, too!
:)
moox. for a new generation.
It's arguable. I've heard nightmare stories about high RPM SCSI drives' reliability. And, from a cost point of view, you could probably buy 4 20 GB IDE drives for the price of one 18GB 15k RPM drive and set them up in RAID-0+1 or -3 and have vastly better reliablity and speed.
Raid 3 is pretty atrocious unless you are reading and writing HUGE files all the time.
Raid 3 has synchronized disk heads, which means all drives will be reading the same stripe, or writing to the same stripe, at the same time.
For best performance with redundancy, Raid 10 (or 0 + 1) is by far the best choice. A Raid10 array gives you 2 different data paths for writing data (just like a 2disk raid0), but gives 4 locations for reading data back (like a 4disk raid0). Plus you still have the redundancy built in where if any single drive failed, no data loss. The downside is that 4 60gb drives will only give you 120gb of usuable space.
--
The parent comment is important, but it is easy not to see the importance.
First, see the Tom's Hardware article about RAID (mirroring/striping) controllers referenced in the parent comment: Fast and Secure: A Comparison of Eight RAID Controllers. As is usual for Tom's Hardware, the article is a bit confused. Apparently it was written hastily.
Motherboards now often have integrated mirroring/striping controllers, so the cost is low. Even Intel has a mother board with an integrated mirroring/striping controller now. In a 2-drive system configured as a mirror, the heads of each drive are moved independently to read data more efficiently than a single drive. Read performance is excellent, and write performance the same as a single drive. Since most systems do more reading than writing, the overall performance is excellent.
A mirror is far more reliable, since if one hard drive fails, all the data can be recovered from the other drive, and the system keeps running until the bad drive can be replaced.
In systems in which there are only one or two users, SCSI is slower. SCSI is only faster when there are many simultaneous users accessing storage.
Extreme solutions such as 15,000 RPM drives and SCSI and RAID 5 are appropriate for e-mail servers, but the noise and expense and lower reliability of the single drives doesn't make sense unless the computer is a server of some type.
Hard drives with a high rotational rate are not necessarily faster at providing data than those with a slow rate. The bottleneck is often the time it takes to move the heads, and the time it takes to present the data to the CPU, not the latency of waiting until the data is under the head.
RAID controllers can do striping, or mirroring, or both. When they do both, 4 drives are required, but read performance is high. Having more than one read head and being able to move them separately is very efficient. A 30,000 RPM drive would still have only one head mechanism.
It is good to see other companies entering the market. Promise Technology was one of the first with low-cost mirroring controllers. Promise is, in my experience, an unbelievably backward company. The products work well, but Promise has sold products with poor setup methods for years. For those who remember DOS programs, the Promise setup user interface is like a DOS shareware program written by a novice programmer who is considerably worse than average in user interface design.
Promise Technology is also known for the poor quality of their manuals. (The company says the manuals are being re-written.)
The parent comment is correct. For most applications, a RAID controller with mirroring, or mirroring plus striping, is excellent.
Market forces drive IDE drives to be built as cheaply as possible while still having the right buzzwords to make consumers believe they're faster than their competitor. RPMs higher than 7200 still don't register with the mass populace, so it's not yet a factor.
SCSI hard drives are all about top-end performance. That's why some SCSI drives cost $1,500 for the same capacity as a $150 IDE drive. It's about being able to reliably move the platter at twice the speed of IDE, and having the correct drive logic and buffer memory to make it useful in the real world, getting very high MTBF numbers, etc..
Comparing typical IDE drives versus high-end SCSI (or FC for that matter) drives is like comparing small asian economy cars with the contenders in the F1 racing series. They have entirely different goals.
11*43+456^2
Do not buy the argument of "market forces" ot "high quality componenets yield high price and low demand". Half of the Slashdot crowd and most of the geeks would all buy 15K IDE drives if available, even if it would cost almost the same as SCSI. Hard disk manufactuerers already make the drives, it is just a question of slapping a IDE controller board vs. SCSI board on the drive. R&D cost is about 0.00001 canadian cent per drive. No additional investment beyond the distribution channel, and viola you have a new product, that can potentially increase your market share. There will be a low but steady demand for these drives, and if any of the manufacturers spend a little money on marketing it can actually turn into the battle of RPM (a la MHz). I do not see why this would not benefit the makers.
Well, this is my opinion, and now you have it.
Peter
Code poet, espresso fiend, starter upper.
--nope, don't want 10 thou or 15 thou drives. What I WANT is a 7x thou drive BUILT with the same specs and bearings as the high speed SCSI drives but limited in rotational speed, ie, "over built for reliability". Slightly more expensive then the ide drives now, cheaper than the scsis. I'll swap bleeding edge expensive over clocked turbo-ized nitroed for reliable-stable-medium powered any day. I don't want it to break. I'll take an 80 gig reliable as heck over a 160 gig might work might not a year from now. I want it to last 20 years not two years or two months. I want built in quiet cooling somehow, too, for that matter.
Are there any such drives out there now?
Mine are at any rate! A Compaq with 4X10K RPM U-W SCSI disks and an external array with five more. Sounds like a jet plane taking off as the controller starts the drives one-by-one :)
But I can see the appeal. True geeks don't give a rat's about noise. Gimme the speed!Resistance is futile. Reactance buggers it up.
As you said in your comment before your question.
It's called a SCSI drive.
For example, here, a 18G 10k RPM SCSI drives cost about the same prive as a 40G IDE 7200 RPM. Warranty of 5 years instead of 1, MTBF of 1-2 Mh instead of 500 kh. And it's even faster.
#include "coucou.h"
The major issue here isn't "can't" so much as "shouldn't".
IDE is targetted at the "at home" user, whereas SCSI is now almost the exclusive domain of businesses looking for performance and haX0rs looking to cut compile times down. The average IDE user just takes the drive, plugs in the cables, and sticks it in... cooling is never even thought of, indeed, you'll be lucky if he puts more than one screw in it.
Even a 10K drive runs HOT. If its on for more than a few days without a fan you're risking your data. A 15K drive that a non-clueful user stuck bare into his PC would be:
1. A support nightmare (hey, you're newfangled hard drive turned into a pile of pudding in my PC)
2. A fire hazard (even if its the customers own damned fault, better to not get him burned to death)
Yeah, but only while they are expensive.
When you think about it, you shouldn't need more than 20GB for your system, apps, and maybe a few games.
Where do you get off telling everyone what to think? Seriously? My system has 80 gig right now, partly because it's a multiboot and I like keeping my disks 30-50% empty because it improves performance.
As far as the slower IDE drive, just spend your money on more RAM for the system and increase the cache.
Beyond a certain point adding RAM doesn't help much, caches only increase in speed marginally for a doubling of the cache size. Adding faster disks helps basically all of the slowest OS tasks go much faster.
And don't rely on the CPU intensive built-in IDE controller on most Intel/AMD motherboards...buy a decent controller card instead.
Yeah right CPU intensive makes a big difference in these days of 3 Ghz processors. Processors are getting faster MUCH faster than drives- the overhead is dropping by a factor of nearly 2 each year.
And if you really want to get ~15000RPM with IDE technology, just get an IDE RAID controller and use striping...using this method you can actually get to much higher theoretical speeds than a single 15000RPM drive. with 4 7200RPM drives you could get up to a theoretical speed of 28800RPM!!!
No. 15000 rpm gives half the latency of any number of 7200 RPM. Latency usually is the bottleneck, not throughput. RAID improves throughput, not latency.
Rule of thumb, unless you have lots of disks on one processor- SCSI is a waste of time and money.
-WolfWithoutAClause
"Gravity is only a theory, not a fact!"With Volume Management, you can build a RAID-4 volume, with the parity "disk" on a Raid-0+1. Best of many worlds - very EMC2 SAN-style.
"Flyin' in just a sweet place,
Never been known to fail..."
I have 4 of them in this machine (Fujitsu MAN-series drives), and they're quieter than anything I've ever used.
- A.P.
"Remember when the U.S. had a drug problem, and then we declared a War On Drugs, and now you can't buy drugs anymore?"
That's historically not the reason in fact, although the spare space is used for this reason.
You can't really make a generalization like that about "UNIX filesystems," because there are so many different types that behave differently.
Only in detail. Every single filesystem I've seen detailed benchmarks for (XFS, FAT32, ReiserFS, ext3, ext2) degrade sharply above the 85% usage point, the exact point varies by a few percent, but in general this occurs.
Anyway, if you don't believe me; no skin off my nose, go ahead max out your disk usage- I don't care if you're filesystem grinds to a halt.
-WolfWithoutAClause
"Gravity is only a theory, not a fact!"